Automatic pull-rod adjuster.



. Inn 870,201. PATENTED NOV. 5, 1907.

H. G. SMITH. AUTOMATIC PULL ROD ADJUSTER.

APPLICATION FILED JAN.10. 1907.

2 SHEETS-SHEET 1.

PATENTED NOV. 5, 1907,

H. G. SMITH. AUTOMATIC PULL ROD ADJUSTER;

APPLICATION FILED JAR.=10. 1907.

' 2 SHBETS-8EERT 2i W3 in 03020 PATENT OFFICE.

HERBERT G. SMITH, OF WAYSIDE, KANSAS.

AUTOMATIC PULL-ROD ADJUSTER.

Specification of Letters Patent.

Patented Nov. 5, 1907.

Application filed January 10. 1907- Serial No. 351,700.

To all whom "it may concern:

Be it known that I, HERBERT G. SMITH, a citizen of the United States, residing at Wayside, in the county of Montgomery and State of Kansas, have invented certain new and useful Improvements in Automatic Pull- Rod Adjusters, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to power transmitting mechanism, and especially to that type used in connection with the pumping of oil wells.

The object of the invention is to provide a simple and inexpensive means for automatically adjusting a pull rod so that any variation in its length caused by temperature conditions will be adjusted at each stroke. Heretofore this adjustment of the pitman or pull rod has been made by hand, sometimes necessitating the stopping of the machine. My invention, by making the adjustment automatic, renders the attention of an attendant unnecessary.

The invention is illustrated in the accompanying drawings in which Figure 1 is a side elevation of a pump jack with my improvement shown thereon. Fig. 2 is an end elevation looking in the direction of the arrow in Fig. 1. Fig. 3 is an enlarged detail of the pull rod support and showing the position of the operating gear in connection with the pivoted frame. Fig. 4 is a modification of the device shown in Fig. l as used independent of the jack. Fig. 5 is an end view of the frame used in Fig. 4, and Fig. (5 is an enlarged detail of the guiding sleeve used in the modification.

i 1 have shown and will describe hereinafter a jack frame 1 of the type which comprises two pair of legs 2 and 3 which are joined at their top to form a support for the jack 4. At the lower end of the jack I provide an open frame 5 which connects the vertical and angular rods of the jack and supports the pull rod 6. In Fig. 1 the pull rod 6 passes through a collar 7 provided with projecting stub shafts 8 on either side thereof which are held within bearings 9 on the frame 5 so that the sleeve may have an oscillating motion with respect to the frame 5 when the jack is reciprocated by the action of the pull rod. At the top and bottom of the frame 5 there are provided lugs 10 which extend laterally therefrom and are provided with hinge pins 11 to which is secured the U shaped frame 12. The pull rod 6 is squared on its sides and is provided with screw threads 13 at its outer end, and threaded thereon is a toothed pinion 14 adapted to engage the outer end of the collar 7. This toothed wheel rides idly over the frame 12 throughout a predetermined arc and the frame is held in engagement with the pinion by a spiral spring 15. Secured to the frame at either terminus of the normal arc travel of the l pinion 14 are projecting teeth 16 and 17 which are adapted to engage the pinion and turn it upon the screw threads 13 so that the length of the pull rod is altered to suit the conditions under which it is operating, for instance if the rod has expanded from heat the backward movement of the jack will be increased and the tooth 17 will contact with the pinion 14 to screw it up upon the threads and thereby reduce the length of the rod with each stroke. Should the rod be contracted from cold or other causes, however, the forward movement of the jack will be increased and the backward movement lessened so that the tooth 16 will engage the pinion l4 and unscrew it upon the threads to thereby increase the length of the rod with each stroke.

In the modification shown in Fig. 4 I have shown the frame 5 detached from the jack and slidably mounted .upon a rod 18. The collar or sleeve '7 in this modification is provided with projecting arms 19 to which the forked ends 20 of the pump rod 21 is connected. The operation is substantially the same as that in Fig. 1.

The end of the pull rod 6 where it projects through the guiding collar 7 and through the pinion 14 is flat tened on its sides so that it will not rotate in the guide sleeve as the pinion is turned but will only have reciprocatory motion therein. I have shown a plurality of holes in the frame 12 so that the teeth 16 and 1'7 may be adjusted toward or away from the pinion so that I may more accurately adjust the pull rod depending upon the length of its stroke.

Although I have shown and described the most specific form of my invention many changes and modifications might be resorted to without in anyway departing from the spirit or scope of my invention and all such changes and modifications I contemplate and consider to be within the scope and purview of the appended clams.

Having thus described my invention what I claim and desire to secure by Letters Patent is:

1. In a device of the class described the combination with a pump jack, of a pull rod connected therewith and means for automatically adjusting the length of the pull rod at every stroke thereof.

2. In a device of the class described the combination with a pump jack, of a guiding sleeve pivoted to said pump jack, a pull rod slidably mounted in said sleeve, means engaging said sleeve for regulating the length of the pull red, and means for operating said regulating means.

In a device of the class described the combination with a pump jack, of a sleeve pivotally secured to said pump jack, a pull rod slidably mounted within said sleeve, a pinion engaging said sleeve and screw threaded on said pull rod, and means for turning said pinion in either direction depending upon the condition of the pull rod.

4. In a device of the class described the combination with a pump jack, guidingmeans pivoted to said pump jack, of a pull rod loosely engaging said guiding means, means for preventing the withdrawal of said pull rod from the guiding means, said means constituting adjusting means for the pull rod, means for operating the adjusting means, and means for holding the operating means in ensaid frame and adapted to engage said adjusting pinion 10 gagement with the adjusting means. to alter the length of the rod according to its temperature In a device of the class described the combination condition.

with a pump jack, of a guiding sleeve pivoted to said pump in testimony whereof I afiix my signature in presence of jack, of a pull rod slidably mounted in said guiding two Witnesses.

means, means for preventing the rotation of said pull rod, HERBERT G. SMITH.

an adjusting pinion threaded on the end of said pull rod, Witnesses:

a hinged frame normally bearing against said pinion and ED I'IEILMAN,

riding idly thereover, and teeth extending from the side of l L. G. KINNEX. 

